/// <summary>
/// Check if this GraphNode can be passed; eg. is it solid of empty?
/// </summary>
/// <param name="startingNode">The node we are travelling from.</param>
/// <returns>True if if the node can be travelled to.</returns>
public override Boolean IsPassable(GraphNode startingNode)
{
// If this GraphNode is not storing a tile, or that Tile is not empty, thats
// an instant fail.
if (!IsEmpty())
{
return false;
}
// We should not have mismatch GraphNode objects, so pData should be Level.Tile in this case.
Level.Tile tile = startingNode.pData as Level.Tile;
// Loop through all adjacent tiles to figure out which direction we are travelling in.
// We need that data in order to determine if this is a legal diagonal move.
for (Int32 i = 0; i < tile.mAdjecentTiles.Length; i++)
{
if (mTile == tile.mAdjecentTiles[i])
{
if (Level.IsAttemptingInvalidDiagonalMove((Level.Tile.AdjacentTileDir)i, tile))
{
return false;
}
else
{
// No need to continue searching.
break;
}
}
}
return true;
}
/// <summary>
/// When finished using a Node which was retrieved from GetNode, pass it back to
/// this function for clean up.
/// </summary>
/// <param name="node"></param>
public void RecycleNode(GraphNode node)
{
node.Reset();
#if DEBUG
node.mInUse = false;
#endif // DEBUG
mUnusedNavMeshTileGraphNodes.Enqueue(node as NavMeshTileGraphNode);
}
/// <summary>
/// These nodes get used over and over again, so we need to make sure they
/// get completely reset between uses.
/// </summary>
public void Reset()
{
mGraphNode = null;
mPrevious = null;
mCostFromStart = 0;
mCostToDestination = 0;
mReached = false;
mPathSolved = false;
}
/// <summary>
/// Renders a single GraphNode and optionally links to all it's neighbours. Derived Graph classes should try
/// to use this function even if overriding DebugDraw so that there is a consistent look to Graph objects.
/// </summary>
/// <param name="node">The GraphNode to render.</param>
/// <param name="showLinks">True to draw links to neighbouring GraphNode objects.</param>
protected virtual void DrawNode(GraphNode node, Boolean showLinks)
{
// Draw the node a circle.
DebugShapeDisplay.pInstance.AddCircle(node.pPosition, 4.0f, Color.DarkRed);
// If requested show the links between this node and all his neighbours.
if (showLinks)
{
for (Int32 j = 0; j < node.pNeighbours.Count; j++)
{
Color costColor = Color.Lerp(Color.White, Color.Red, (node.pNeighbours[j].mCostToTravel - 8.0f) / (3.0f * 11.134f));
DebugShapeDisplay.pInstance.AddSegment(node.pPosition, node.pNeighbours[j].mGraphNode.pPosition, costColor);
}
}
}
/// <summary>
/// Doesn't actually do anthing different in Release, but in Debug it does some checks for
/// duplicate entries. Doing this for all Graph objects would be too expensive even for testing.
/// </summary>
/// <param name="node">The node to add.</param>
public override void AddNode(GraphNode node)
{
/*
for(Int32 i = 0; i < pNodes.Count; i++)
{
if (pNodes[i].pPosition == node.pPosition)
{
//System.Diagnostics.Debug.Assert(false, "Attempting to add GraphNode at dupe position.");
}
if (pNodes.Contains(node))
{
//System.Diagnostics.Debug.Assert(false, "Attempting to add Dupe GraphNode.");
}
}
*/
base.AddNode(node);
}
/// <summary>
/// Update where this Planner is travelling from. The position is used to look up a tile at that
/// position in the world.
/// </summary>
/// <param name="source">The position in the world that the planner will start at.</param>
public Boolean SetSource(GraphNode source)
{
//System.Diagnostics.Debug.Assert(source != mEnd || source == null, "Source and Destination are the same.");
//HPAStar.NavMesh.DebugCheckNode(source);
if (mStart != source)
{
mStart = source;
mPathInvalidated = true;
mSolved = false;
return true;
}
return false;
}
/// <summary>
/// Similar to SetDestination, except in this case the existing path is not invalidated. Instead
/// the path searching continues as if the supplied destination were the original destination.
/// </summary>
/// <param name="destination">The node to try and reach.</param>
/// <returns></returns>
public Boolean ExtendDestination(GraphNode destination)
{
if (mEnd != destination)
{
// Make sure that we are not trying to extend the destination
// to a Node that has already be Closed. If that is the case
// then the path needs to be regenerated with fresh data.
for (Int32 i = 0; i < mClosedNodes.Count; i++)
{
if (mClosedNodes[i].pGraphNode == destination)
{
//DebugMessageDisplay.pInstance.AddConstantMessage("Extending with closed node.");
return SetDestination(destination);
}
}
mEnd = destination;
// If the path was previously solved, it is not any longer.
mSolved = false;
// If the path was already solved, it needs to be told otherwise.
mBestPathEnd.pPathSolved = false;
return true;
}
return false;
}
/// <summary>
/// Checks if a Node and it's neighbours are erronously flagged as being not in use or contain
/// null data.
/// </summary>
/// <param name="node">The node to check. The node assumed to be in use.</param>
static public void DebugCheckNode(GraphNode node)
{
if (node is NavMeshTileGraphNode)
{
System.Diagnostics.Debug.Assert(node.mInUse, "Node being used but flag as not in use.");
System.Diagnostics.Debug.Assert(node.pData != null, "pData is null.");
for (Int32 j = 0; j < node.pNeighbours.Count; j++)
{
System.Diagnostics.Debug.Assert(node.pNeighbours[j].mGraphNode.mInUse, "Node being used but flag as not in use.");
System.Diagnostics.Debug.Assert(node.pNeighbours[j].mGraphNode.pData != null, "pData is null.");
}
}
}
/// <summary>
/// Take two GraphNode objects and remove any link they have as Neighbour.
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
public void UnlinkGraphNodes(GraphNode a, GraphNode b)
{
a.RemoveNeighbour(b);
b.RemoveNeighbour(a);
//if (a != null)
//{
//DebugWalkGraphForErrors(a as NavMeshTileGraphNode);
//}
//DebugCheckNode(a);
//DebugCheckNode(b);
}
/// <summary>
/// Removes a Neighbour by looking at the GraphNode stored in each one.
/// </summary>
/// <param name="neighbour">The GraphNode in the Neighbour that should be removed.</param>
public virtual void RemoveNeighbour(GraphNode neighbour)
{
for (Int32 i = 0; i < mNeighbours.Count; i++)
{
if (mNeighbours[i].mGraphNode == neighbour)
{
//HPAStar.NavMesh.DebugCheckNode(mNeighbours[i].mGraphNode);
mNeighbours[i].Reset();
// Put this Neighbour back into the Queue so others can reuse it.
mUnusedNeighbours.Enqueue(mNeighbours[i]);
mNeighbours.RemoveAt(i);
// Should be no dupes so return after finding one.
return;
}
}
}
/// <summary>
/// Adds a neighbour to this GraphNode.
/// </summary>
/// <param name="node">The neighbouring GraphNode.</param>
/// <param name="cost">
/// The cost to travel from this GraphNode to <paramref name="node"/>. If not supplied the cost will
/// be the distance between the two GraphNode objects.
/// </param>
public virtual void AddNeighbour(GraphNode node, Single cost)
{
//HPAStar.NavMesh.DebugCheckNode(node);
// Create a new neighbour to wrap the node passed in.
Neighbour temp = mUnusedNeighbours.Dequeue();
// Put it back into a default state.
temp.Reset();
temp.mGraphNode = node;
if (cost >= 0)
{
temp.mCostToTravel = cost;
}
else
{
// This assumes that nodes never move.
temp.mCostToTravel = Vector2.Distance(node.pPosition, pPosition);
}
System.Diagnostics.Debug.Assert(node.pData != null, "Uninitialized node set as neighbour");
mNeighbours.Add(temp);
}
/// <summary>
/// Adds a neighbour to this GraphNode.
/// </summary>
/// <param name="node">The neighbouring GraphNode.</param>
/// <param name="cost">
/// The cost to travel from this GraphNode to <paramref name="node"/>. If not supplied the cost will
/// be the distance between the two GraphNode objects.
/// </param>
public virtual void AddNeighbour(GraphNode node)
{
AddNeighbour(node, -1.0f);
}
/// <summary>
/// Removes a GraphNode from the Graph.
/// </summary>
/// <param name="node"></param>
public virtual void RemoveNode(GraphNode node)
{
mNodes.Remove(node);
}
/// <summary>
/// Adds a GraphNode to the Graph.
/// </summary>
/// <param name="node">The node to add.</param>
public virtual void AddNode(GraphNode node)
{
mNodes.Add(node);
}
/// <summary>
/// Clear out the destination that the planner is trying to reach. This doubles as a way
/// to stop the planner from trying to advance.
/// </summary>
public void ClearDestination()
{
mEnd = null;
mSolved = false;
// Release the Nodes. We don't need them anymore. If a new destination
// is set, we will need to start from scratch anyway.
ClearNodeLists();
}
/// <summary>
/// Helper method for checking if any of the Neighbours of this GraphNode contain a
/// supplied GraphNode.
/// </summary>
/// <param name="neighbour"></param>
/// <returns></returns>
public virtual Boolean HasNeighbour(GraphNode neighbour)
{
for (Int32 i = 0; i < mNeighbours.Count; i++)
{
if (mNeighbours[i].mGraphNode == neighbour)
{
return true;
}
}
return false;
}
/// <summary>
/// Return the planner to its original state.
/// </summary>
public void Reset()
{
mStart = null;
ClearDestination();
ClearNodeLists();
}
/// <summary> /// Check if this GraphNode can be passed; eg. is it solid of empty? /// </summary> /// <param name="startingNode">The node we are travelling from.</param> /// <returns>True if if the node can be travelled to.</returns> public abstract Boolean IsPassable(GraphNode startingNode);
/// <summary>
/// Links two GraphNode objects as Neighbour. Does the slightly expensive task of calculating actual
/// A* path between the two, and caches that value as the cost between the two.
/// </summary>
/// <param name="a">A node to link to <paramref name="b"/>.</param>
/// <param name="b">A node to link to <paramref name="a"/>.</param>
/// <param name="cluster">The cluster containing both nodes.</param>
private void LinkGraphNodes(GraphNode a, GraphNode b, Cluster cluster)
{
Boolean oneWay = false;
mPlanner.Reset();
mPlanner.SetSource((a.pData as Level.Tile).mGraphNode);
mPlanner.SetDestination((b.pData as Level.Tile).mGraphNode);
// Do a standard A* search with the adde constraint of staying within the
// bounds of this cluster.
Planner.Result result = mPlanner.PlanPath(cluster.pBounds, false);
// Keep searching unti we either fail or succeed.
while(result == Planner.Result.InProgress)
{
result = mPlanner.PlanPath(cluster.pBounds, false);
}
// Only connect the nodes if they can be reached from one another within the same cluster.
if (result == Planner.Result.Solved)
{
PathNode path = mPlanner.pCurrentBest;
// Link the two neightbours.
a.AddNeighbour(b, path.pFinalCost);
if (!oneWay)
{
b.AddNeighbour(a, path.pFinalCost);
}
}
mPlanner.ClearDestination();
//if (a != null)
//{
//DebugWalkGraphForErrors(a as NavMeshTileGraphNode);
//}
//DebugCheckNode(a);
//DebugCheckNode(b);
}
/// <summary>
/// Put this object into a default state.
/// </summary>
public void Reset()
{
mGraphNode = null;
mCostToTravel = 0;
}
/// <summary>
/// Helper function for creating a Node for an entrace but also checking that it hasn't already been
/// created, and if it has, just using that one instead to avoid multiple Nodes on top of the same
/// tile.
/// </summary>
/// <param name="cluster">The custer which this node lives in.</param>
/// <param name="tile">The tile which this node wraps.</param>
/// <param name="node">
/// If a node already exists over <paramref name="tile"/> this will be that GraphNode. If not it will
/// be a newly created GraphNode.
/// </param>
/// <returns>True if a new GraphNode was created.</returns>
private Boolean CreateEntraceNode(Cluster cluster, Level.Tile tile, out GraphNode node)
{
Boolean created = false;
// First see if this Tile is already managed by this cluster. If it is, it will return us
// the node which contains it.
node = cluster.GetNodeContaining(tile);
// If the node isn't already being managed, we need to create a new one.
if (null == node)
{
node = mNodeFactory.GetNode();
node.pData = tile;
created = true;
// New nodes need to be registers with the Graph.
AddNode(node);
}
return created;
}
/// <summary>
/// Check if this GraphNode can be passed; eg. is it solid of empty?
/// </summary>
/// <param name="startingNode">The node we are travelling from.</param>
/// <returns>True if if the node can be travelled to.</returns>
public override Boolean IsPassable(GraphNode startingNode)
{
// This Node would never have been created if it weren't passable.
return true;
}
/// <summary>
/// Removes a GraphNode from the Graph and also removes all the associated links to and from other
/// GraphNode objects in this Graph.
/// </summary>
/// <param name="node">The GraphNode to remove.</param>
public void RemoveTempNode(GraphNode node)
{
Cluster cluster = GetClusterAtPosition(node.pPosition);
if (null != cluster)
{
for (Int32 i = 0; i < cluster.pNodes.Count; i++)
{
if (node != cluster.pNodes[i])
{
UnlinkGraphNodes(node, cluster.pNodes[i]);
}
}
cluster.RemoveNode(node);
}
//DebugCheckForReferences(node);
mNodeFactory.RecycleNode(node);
RemoveNode(node);
//DebugCheckNodes();
}
/// <summary>
/// Update the location that the Planner is attempting to reach. The position will be used
/// to look up the tile at that position in the world.
/// </summary>
/// <param name="destination"></param>
public Boolean SetDestination(GraphNode destination)
{
if (mEnd != destination)
{
mEnd = destination;
mPathInvalidated = true;
mSolved = false;
return true;
}
return false;
}
/// <summary>
/// Checks if a node is reference by any Node in the Graph and their neighbours.
/// </summary>
/// <param name="node">The node to search for.</param>
public void DebugCheckForReferences(GraphNode node)
{
for (Int32 i = 0; i < pNodes.Count; i++)
{
GraphNode next = pNodes[i];
for (Int32 j = 0; j < next.pNeighbours.Count; j++)
{
GraphNode nextNeighbour = next.pNeighbours[j].mGraphNode;
System.Diagnostics.Debug.Assert(nextNeighbour != node, "Found node!");
}
}
}
/// <summary>
/// Constructor.
/// </summary>
/// <param name="node">The GraphNode this PathNode will wrap.</param>
public PathNode(GraphNode node)
{
mGraphNode = node;
}